S&C Instruction Sheet 712-501
9
Indicators
REPLACE:
There are two red zones . If the indicator needle
is in the red zone shown in Figure 7, the gas
density in the interrupter has dropped below the
minimum functional level and the interrupter
will not maintain full interrupting or dielectric
ratings . The interrupter should be removed from
service and replaced promptly . Do not operate
the Mark VI Circuit-Switcher .
If the indicator needle is in the red zone
shown in Figure 8, the local gas-density gauge
is damaged, and cannot be relied on to pro-
vide an accurate indication of gas density .
The pole-unit should be removed from service
and replaced promptly . Contact your local
S&C Sales Office . Do not operate the Mark VI
Cir cuit-Switcher .
NOTICE
At temperatures below -31°F (-35°C), the
indicator needle will be in the red zone due
to the cold temperature . The gas density is
below the minimum functional level, so the
interrupter will not have full interrupting or
dielectric ratings .
At these temperatures,
the gas-pressure gauge does not pro-
vide accurate indication of whether an
interrupter is losing SF
6
.
Figure 7. Gauge needle in red “REPLACE” zone.
“REPLACE” zone
Figure 8. Gauge needle in red “REPLACE” zone.
“REPLACE” zone
Summary of Contents for Mark VI
Page 28: ...Printed in U S A ...
